Lens mount



Nov. 10, .1931.

K. KRUENING LENS MOUNT Original Filed Jan. 25. 1928 INVENTOR.

. Q G, I I Mm 4 ATTORNEYS.

Patented No 1931 UNITED STATES PATENT OFFICE KARL KRUENING, OF JAMAICA, NEW YORK, ASSIGNOR '10 KOLLMORGAN OPTICAL 'OOR- PORATION, OF BROOKLYN, NEW YORK, A CORPORATION OFNEW YORK LENS MOUNT I griginal application filed January 25, 1928, Serial No. 249,223. Divided and this application filed July 18,

. 1929. Serial No. 879,187. g

This invention relates to mounts for lenses,

' with particular reference to the mounting of projection-lenses in the motion picture industry', although of course not limited to this use. Such a'lens system is usually composed of four lenses, one pair being cemented together and to be termed hereinafter the front element, while the two lenses of the other set and to be termed hereinafter the rear element are separable, that is'usually not cemented to eachother. Inasmuch as these lenses must be removed from their mounts from time to time for cleaning purposes the lenses through ignorance or carelessness are often reversed or become inserted in the wrong position resulting in images of very poor quality.

The present invention has for an object the provision of a construction wherein this possibility is! overcome.

In the accompanying drawings: Fig. 1 is a view in side elevation partly in section of a lens system constructed in accord- 'ance with this invention; and

Fig. 2 is a section on the line 2-2 of Fig. 1. Referring to the drawings in detail, 1 designates a lens tube. 2 and 3 designate the the ring to be screwed into the lens tube 1.

The lenses are tapered on their periphery as shown at 8 and the interior of the lens retaining ring 4 is similarly tapered. This tapered. construction positively prevents in-' sertion ofthe lenses in reversed position in the ring 4.

9 designates a clamping ring whichlis threaded on itsexterior and screws into the internally threaded end of the ring 4 for clamping the lenses against the shoulder 5.

The rear element is composed of separable lenses 10 and 11, these lenses being smaller in diameter than the front element and hence not interchangeable therewith. The lenses 10 and 11 also differ from each other.-

12 designates a. retaining tube for this rear ing ring being tapered internall element, this being screwed into the lens tube 1. This retaining tube is tapered internally as shown at 13 and shouldered as ndicated at 14. The lens 11 is. correspondmgly tapered onit's periphery and hence can- {Iottmbe inserted incorrectly 1n the retaining Thelens 10 is provided with a clamping ring 15 spun about its periphery, the peri hery of this clamping ring being threade as indicated at 16 so as to screw into the retaining tube 12. The clamping ring 15 can only be inserted in the retaming tube 12 correctly, the end portion 17 being of larger diameter than the threaded portion.

It will be seen, therefore, that the presentinvention provides a construction wherein the lenses of both the front element and the rear element must always be inserted correctly.

This application is a division of my co- Sending application Serial No. 249, 223, filed anuary 25, 1928.

What I claim is 1. In projec.or ap aratus the combination of a lens tube, a ront element comprising a pair of lenses, a lens retaining ring therefor threaded to said tube, said retainthroughout part of its len h and t e periphery of the lenses being correspondingly tapered to prevent reversal of the lenses in the rmg, and said ring having a straight internally threaded portion extending beyond the face of the lenses, and a clamping ring threaded'into said projecting portion of the retain ing ring.

2. In pro'ector apparatus the combination a of a lens tu e, a front element comprising a lens retaining ring threaded to said tube and provided with a taper on its interior and with a shoulder at the outer end of the taper,

a pair of lenses having their periphery ta- 1 pered and adapted to be received by the tapered interior of the lens retaining ring, the rear end of said ring being straight and projecting beyond the plane of said lens and a clamping ring threaded to the straight portion of the retaining rin forclamplng said lenses against said shoul er.

3. In projector apparatus a rear element comprising a pair of separable lenses, a lens retaining ring tapered internally and provided with an internal shoulder, one of said lenses having a tapered periphery and adapted to be received by the tapered portion of said retaining ring, and a straight sided clamping ring secured to the other of said lenses and adapted to screw into an untapered portion of the saidretaining ring to force the first mentioned lens against said shoulder.

4. In projector apparatus a rear element comprising a pair ofiseparable lenses, a lens retaining ring, one of said lenses having a tapered periphery, and said rin being c012 respondingly tapered internally or receiving said lens, a straight sided clampin ring secured to the other of said lenses an adapted to screw into a straight sided portion'of said retaining ring which projects beyond the first mentioned lensto clamp the first mentioned lens in place, said clamping ring at its outer end being shouldered to engage the face of the retaining ring whereby reversal in the retaining ring of the clamping ring and hence of the lens carried thereby is prevented.

This specification signed this 12thday of July, 1929. i

KARL KRUENING. 

